OK but the real question is what’s up with the two 1800 transitions. They’re synonyms for each other. It’s Australia/Lord_Howe, which has a powerful 30-minute DST transition:
<+1030>-10:30<+11>-11,M10.1.0,M4.1.0
10h30m ahead of UTC standard, 11h DST. Love this for them. Running cron jobs on an hourly basis doesn’t in practice have very weird interactions with DST. Everywhere else on the planet, every 60 minutes you’re back to the same spot on the clock.
Except Lord Howe Island. Heroes. On the first Sunday of October, a 60-minute timegap only puts you halfway around the clock. All your cron jobs are now staggered relative to the local wall clock.
